1. Field of the Invention
The present invention relates to a method for producing mushroom mycelia. More particularly, the present invention relates to production of mushroom mycelia by use of water from the washing of grains (hereinafter just as grain-washing water) as a culture medium, and by use of trace minerals as nutrient additives for the culture medium. Also, the present invention is concerned with the use of the mushroom cultures in raising ducks.
2. Description of the Prior Art
For their medicinal or healthful effects, many mushrooms have attracted keen attention. At present, mushroom mycelia for use in materials for medicines and foods are extensively produced in many countries through broth culture. For instance, Tremella auranita is cultured in broths and commonly used as an additive for walnut confectionery, crackers, breads, and beverages in China. More medicinal components from mushroom mycelia have been developed in Japan. Krestin (PS-K) obtained from mycelium cultures of Coriolus versicolor by hot water extraction, sizofilan obtained from mycelium cultures of Schizophyllum commune, and lentinan from Lentinus edodes have been commercialized as antitumor active materials. In Korea, mycelia obtained from Ganoderma lucidum, Coriolus versicolor, Phellinus Linteus, and Cordyceps sinensis are developed into materials for beverages and cosmetics.
However, such medicinally useful mushroom mycelia are produced at relatively high cost, although such costs have been gradually reduced. For example, the culture media are very expensive. Therefore, there remains a need for an improved method or system that can culture such medicinal mushroom mycelia effectively and at low cost.
In addition to medicinal/anti-tumorigenic polysaccharides, trace minerals such as chrome, selenium and germanium are found in mushrooms. As their effects on the physiology of the human body have been revealed, trace minerals are now regarded as important immunological and medicinal components. In fact, humans or animals deficient in trace minerals are apt to become diseased. For example, diabetic mellitus is aggravated by insufficient chrome or zinc, because the minerals provide environments necessary for the activity of insulin, thereby improving the medicinal effect of insulin. Found abundantly in yeast, chromium is the central atom in the glucose tolerance factor (GTF), which works with insulin to transport glucose from the blood into body cells, regulating blood sugar levels. Lack of selenium may be a cause of cancer and is also found to deepen senility and cause arteriosclerosis. Since the finding that medicinally useful plants such as ginseng and wild ginseng are rich in germanium, this trace mineral has been extensively studied for use in antitumor agents, hepatitis medications, and functional foods for immunity enhancement.
Fewer minerals are found in soils which have been treated with chemical fertilizers for long time periods. At present, yeasts are utilized as sources of chromium, selenium and germanium. Additionally, extensive attention is paid to mushrooms such as Ganoderma lucidum and Coriolus versicolor because of their richness in trace minerals such as chromium, selenium and germanium. Therefore, mushroom mycelia can be exploited as biomaterials for health foods, functional foods and medicines because they contain anti-tumorigenic polysaccharides and trace minerals.
Recent, it has been reported that pigs raised with feedstuff containing chromium picolinate grow fast, with an increase in muscle and a decrease in body fat. The same was found to be true of mice. There is possibility that other animals can be raised with the same effects when fed with chromium.
Leading to the invention, the intensive and thorough research into mushroom mycelium culture, conducted by the present inventors aiming to reduction in production cost, resulted in the finding that mushroom mycelia can be effectively grown in broths containing the water from the washing of grains, such as rice, glutinous rice, barley, wheat, millet, glutinous sorghum, glutinous hog millet, and Job""s-tears. Addition of trace minerals to a culture broth made mushroom mycelia rich in the minerals. It was also found that, when being raised with feedstuffs added with the mushroom culture, ducks give delicious meats, which was also rich in nutrients.
It is therefore an object of the present invention to provide a method for culturing mushroom mycelia at low production cost with efficiency.
It is another object of the present invention to provide beverages with medicinal or healthful functionality.
It is a further object of the present invention to provide a method for raising ducks producing high quality meats.